A208285 Number of n X 6 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 1 0 vertically.

26, 676, 4374, 16872, 49130, 119580, 256774, 502416, 914778, 1572500, 2578774, 4065912, 6200298, 9187724, 13279110, 18776608, 26040090, 35494020, 47634710, 63037960, 82367082, 106381308, 135944582, 172034736, 215753050, 268334196

Offset

1,1

Comments

Column 6 of A208287.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = (8/15)*n^6 + (23/3)*n^5 + (82/3)*n^4 + (1/3)*n^3 - (178/15)*n^2 + 2*n.

Conjectures from Colin Barker, Jun 29 2018: (Start)

G.f.: 2*x*(13 + 247*x + 94*x^2 - 230*x^3 + 65*x^4 + 3*x^5) / (1 - x)^7.

a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>7.

(End)

Example

Some solutions for n=4:
..0..1..0..1..1..0....0..1..1..1..1..0....1..1..1..1..0..0....1..0..1..0..1..0
..0..1..0..1..0..1....1..0..1..1..0..1....1..1..0..1..1..1....0..1..0..1..0..1
..0..1..0..1..0..0....0..1..1..1..1..0....1..1..1..1..0..0....1..0..1..0..1..0
..0..1..0..1..0..0....1..1..1..1..0..1....1..1..0..1..1..0....1..0..1..1..1..1

Crossrefs

Cf. A208287.

Sequence in context: A207952 A207861 A207811 * A208418 A208026 A207806

Adjacent sequences: A208282 A208283 A208284 * A208286 A208287 A208288

Keyword

nonn

Author

R. H. Hardin, Feb 25 2012

Status

approved